Update:Chicago hospital Shooter is a jilted lover who killed his ex-fiance, a cop, and pharmacy worker after he demanded for his ring back

The man who opened fire at a hospital killing and injuring people has been identified as Juan Lopez, a jilted lover.

32-year-old Lopez, a Chicago Housing Authority worker, was engaged to Dr Tamara O’Neal, 38, and they were to wed on October 27, but she ended the engagement in September.

Lopez stormed Mercy Hospital in Chicago on Monday and demanded to have his ring back before he repeatedly shot Dr Tamara in the parking lot of the hospital. After killing his former fiancee, Lopez went inside the hospital where he shot dead 25-year-old pharmacy resident Dayna Less and Chicago police officer Samuel Jimenez, 28. He then shot another police officer but the officer escaped unhurt as the bullet lodged in the barrel of his handgun while it was holstered on his belt.

Dr Tamara O’Neal with Lopez’s mother, who referred to her as ‘my future daughter-in-law’

The rampage ended when Lopez was eventually shot dead by SWAT officers.

Witnesses said the shooting began around 3.30pm when Lopez confronted Dr O’Neal in the parking lot. She was wearing her medical scrubs and was about to start her shift at the hospital.

Lopez demanded Dr Tamara O’Neal give back the ring he gave her but she said she didn’t have it there with her. He then shot her three times. He stood over her body and fired three more rounds, witnesses said, before making his way inside the hospital.

Once inside, he killed a first-year pharmacy resident who was engaged to be married. He also killed a cop who is a married father-of-three and had only just completed his probationary period on the Chicago police force.

Officer Samuel Jimenez was fatally shot